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3 years ago

Muscles in animals are often found in pairs, because

1 answer:

4 0

I'm not sure how exactly you wanted this question to be answered. You're either talking about the symmetry where animals would have two legs or two arms for example and thus producing a pair of each muscle on both sides of the body, or you're refering to the development of agonistic and antaonistic muscles where each of them served a different purpose; either extending or contracting.

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The first animals to live successfully on land were

Dennis_Churaev [7]

I believe the correct answer will be A

8 0

3 years ago

A teacher says she has identified an organism with these characteristics: eukaryotic, multicellular, autotrophic, and a cell wal

Vilka [71]

Answer;

Kingdom plantae.

Explanation;

Kingdom plantae is a classification kingdom made up of eukaryotic, multicellular organisms that have cell walls made mostly of cellulose.

They have pigments (chlorophyll) that absorb light, and that supply energy and oxygen to themselves and to other life-forms through photosynthesis

They are Eukaryotes, multicellular, autrotrophs, and have cell walls are made of cellulose, and are also producers in an ecosystem.

8 0

3 years ago

Read 2 more answers

Actin filaments are part of the contractile machinery in smooth muscle cells of eukaryotic organisms. Which organelle is respons

TEA [102]

The interaction of motor proteins such as dynein, is responsible for the movement of organelles in cells which uses energy to move parts of the cytoskeleton. Cytoskeleton is a network of intermediate filaments, microtubules and microfilaments that outspread throughout the cytoplasm and serve a variety of signaling, transport and mechanical functions.

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3 years ago

In some breeds of mice, yellow coat color is

Elis [28]

In the exposed lethal genes cause the individual's death during embryionic development before being born. H0m0zyg0us dominant individuals do not get born. Yellow: 2/3. Grey: 1/3. Phenotypic ratio: 2:1

<h3>What is complete dominance?</h3>

When the dominant allele completely masks the expression recessive allele, we talk about complete dominance.

This is the case of individuals that are heter0zyg0us for a particular gene and express the dominant trait.

The dominant allele is hiding the expression of the recessive allele.

<h3>What are the lethal genes?</h3>

Refer to genes that impede the normal development of the individual.

They can cause death during embryo development before the individual gets born,

They can cause the individual's death after being born and before reaching sèxual maturity.

Let us assume that mice color is coded by a single diallelic gene that expresses complete dominance.

Available data:

Yellow color is dominant over grey color.

Yellow is coded by the dominant allele Y
Grey is coded by the recessive allele y

Genotype YY → Yellow and lethal

Genotype Yy → Yellow

Genotype yy → Grey

The cross would be as follows,

Cross: Yy x Yy

Gametes) Y y Y y

Punnett square) Y y

Y YY Yy

y Yy yy

F1) Considering ONLY the successfully born individuals

Genotype

2/3 = 50% of the progeny is expected to be heter0zyg0us, Yy.

1/3 = 25% of the progeny is expected to be h0m0zyg0us recessive, yy.

Phenotype

2/3 = 50% of the progeny is expected to be yellow, Yy.

1/3 = 25% of the progeny is expected to be grey, yy.

The phenotypic ratio is 2:1

You will learn more about lethal genes at

brainly.com/question/13654244

brainly.com/question/14932405

5 0

2 years ago

An Allele that appears or expresses itself over a recessive trait is called a/an dominant allele recessive allele mutation gene

damaskus [11]

Q1. The answer is: a dominant allele.

An allele that appears or expresses itself over a recessive trait is called a dominant allele. Alleles can be dominant or recessive. Dominant alleles are responsible for dominant traits and if two dominant alleles are found together, a dominant trait will be expressed. Similarly, if two recessive alleles are found together, a recessive trait will be expressed. However, if both recessive allele and dominant allele are found together, the recessive allele will be masked by the dominant allele and a dominant trait will be expressed.

Q2. The answer is: homozygous.

If an organism that has two of the same alleles for a trait it is said to be homozygous. If it has two dominant alleles, it is dominant homozygous. If it has two recessive alleles, it is recessive homozygous. If an organisms have two different alleles (one dominant and one recessive), it is said to be heterozygous.

Q3. The answer is: An allele is a single form of a gene inherited from one parent.

Genes are sequences of nucleotides, or parts of genetic information, that are responsible for different traits. Different forms of genes are called alleles. Each gene has two alleles - one inherited from a mother and another inherited from a father.

Q4. The answer is: heterozygous.

If a person has two different alleles for a certain trait like eye color we call that heterozygous. If a person has two same alleles for a certain trait, it is called homozygous. If both alleles are dominant, it is called dominant homozygous. If both alleles are recessive, it is called recessive homozygous. However, if two different alleles (one dominant and one recessive) are found together, it is called heterozygous.

Q5. The answer is: DNA

A gene is a small segment of DNA that codes for a certain trait. One of the organelles inside the cells is the nucleus. The genetic material of the cell is found inside the nucleus. It is in the form of chromosomes, a complex of DNA and proteins. Further, a small segment of DNA that codes for a certain trait is called a gene.

Q6. The answer is: 46.

Almost all human cells have 46 chromosomes. These cells are diploid which means that it has two sets of chromosomes. There are two pairs of 23 chromosomes, each one from each parent. Only gametes have 23 chromosomes. They are haploid and have only one set of chromosomes.

Q7. The answer is: 2 alleles.

Alleles are different forms of genes. Each gene has two alleles. One allele is inherited from a mother and one allele is inherited from a father. So, for each gene, offspring will receive two alleles, each one from each parent.

Q8. The answer is True.

Organisms get one allele for each trait from each parent. Alleles are different forms of genes. Each gene responsible for a certain trait has two alleles. One allele is inherited from a mother and another allele is inherited from a father.

Q9. The answer is: False!

Genotype is the actual gene makeup. On the other hand, phenotype is physical appearance of a genotype. So, genotype is the sum of all genes of an organism. Phenotype is observable characteristic of an organism and it is determined by genotype, but also by environmental factors.

Q10. The answer is: False!

A child having blonde hair is an example of phenotype. Genotype is the sum of all genes of an organism. If we talk about all genes responsible for the blonde hair, we would talk about genotype. But, here is an example of observable physical characteristic, such is the blond hair, so it is an example of phenotype.

Q12. The answer is: genotype.

Genotype is the sum of all genes of an organism. Phenotype is observable characteristic of an organism determined by its genotype. In this question, Rr represents genotype of the organism. On the other hand, the capability of rolling their tongue would be phenotype.

Q13. The answer is: heterozygous.

If an organism has two dominant alleles found together, it is dominant homozygous. The genetic combination is labelled with two capital letters: CC.
If an organism has two recessive alleles found together, it is dominant homozygous. The genetic combination is labelled with two small letters: cc.
If an organism has one dominant and one recessive allele, it is heterozygous. The genetic combination is labelled with one capital and one small letter: Cc.

Q14. The answer is: homozygous dominant

Dominant alleles are labelled with capital letters (for example, C). Recessive alleles are labelled with small letters (for example, c). Homozygous dominant organism has combination CC. Homozygous recessive organism has combination cc. Heterozygous organism has combination Cc.

Q15. The answer is: Homozygous recessive.

The genetic combination cc is an example of homozygous recessive. If the genetic combination was CC, it would be homozygous dominant. If the genetic combination was Cc, it would be heterozygous. This is because only dominant alleles are labelled with capital letters.

7 0

3 years ago