Answer;
Cell
Explanation;
-The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
-Cell is the basic unit and building block of life. It is bound by a cell membrane, and possesses a nucleus which acts as its brain. Arachnoidiscus ehrenbergi is an example of diatoms which are unicellular, therefore it is a cell.
Answer:
This question lacks options, the options are:
A. Only recessive alleles are inherited from homozygous parents.
B. Dominant alleles grow weaker as they are passed from parents to offspring.
C. Only the parent with a dominant allele can pass that allele to offspring in sexual reproduction.
D. A heterozygous parent has an equal chance of passing either the dominant allele or the recessive allele to offspring.
The answer is D
Explanation:
This question involves a single gene coding for hair length in dogs. The allele for short hair (S) is dominant over the allele for long hair (s). This means that allele 'S' will always mask the phenotypic expression of allele 's' in a heterozygous state.
According to the question, two heterozygous dogs (Ss) were crossed to produce 6 shortt-haired offsprings and 2 long-haired offsprings. An heterozygous organism is that which contains two different alleles for a particular gene i.e. a combination of dominant and recessive alleles.
Based on this, during meiosis or gamete formation, an heterozygous dog (Ss) will produce gametes with the short hair allele (S) and long hair allele (s) in equal proportion i.e. 50-50. When the two gametes containing the recessive alleles (s) produced by each heterozygous parent fuses, an offspring with a recessive phenotype (long hair, ss) is produced.
Hence, a long-hair
phenotype can appear in the offspring of two short-haired dogs because a heterozygous parent has equal chance of passing either the dominant or recessive allele to the offspring.
<span>When a gene changes within a population over time, it is referred to as evolution. This refers to a long but steady rate of mutations that occur in genes of organisms within the environment. A lot of factors affect a population's evolution (e.g. climate, reproduction, food source) and it is a determinant whether a species will survive for the next generations. </span>
