1. breeding of individuals that have genes for two different characteristics:
DIHYBRID CROSS.
We call it a dihybrid cross when we are considering a cross between two different traits.
"di" means having two traits involved (for example, trait A and trait B), the "hybrid" means that each trait will have two different alleles (for gene A: A or a; for gene B: B or b), one is dominant and the other is recessive.
2. a grid system used to predict possible combinations of genes due to random fertilization: PUNNETT SQUARE
The Punnett square is a grid system that helps us predict an outcome of a cross or a breeding experiment. We this, we can determine the probability of an offspring having a particular genotype.
This is very useful when we are considering more than one gene, making it less confusing.
3. a condition in which both alleles are dominant: CODOMINANCE
Tere are alleles that have the capacity of dominating at the same time, and when an organism is heterozygotic, both alleles are expressed.
For example, a white chicken(WW) crossed with a black chicken (BB): 100% of the offspring being WB. With this genotype, they have black feathers and white feathers. It's not a blend of colors, but a case where both are expressing.
4. when more than two alternatives exist for a gene: MULTIPLE ALLELES
Mendel thought that only two possible alternatives could exist for a gene, but there are cases that have more than 3 possibilities. Some of those can be really popular in a population while others not so much.
This happens with rabbit's fur. They can be black, brown, grayish,
Himalayan patterning or white fur.
5.a condition in which neither pair of alleles is dominant or recessive, so the traits blend in the phenotype: INCOMPLETE DOMINANCE
Some alleles are not completely dominant, and when that's the case the phenotype of a heterozygous organism will be a mix between the phenotypes of its homozygous parents.
For example:
plant 1: RR -red
plant 2: rr-white
By crossing this plants we will obtain 100% of the offspring with a color mix: pink.(genotype: Rr)
Red and white are not completely dominating so it results in a blend of colors.
Crossing over happens in Meiosis 1 only. In Prophase 1 a cells chromatin (chromatin = chromosomes that have not condensed yet) condense and pair up forming homologous chromosomes (paired = XX (2 chromosomes together)). When this happens segments/ alleles of the chromosomes pairing up swap over. This creates genetic diversity as each chromosome is different, it has parts from its pair. This leaves every chromosome unique and individual.
I hope this helps, sorry some of the vocab is rather technical. By the way I would suggest watching the
'Crash Course: Meiosis' on YouTube, this really helped me when I was learning this topic. :D
Answer:
I believe it is false so I hope you get it right
Answer:
The correct answer would be - Characteristics can be lost in evolution.
Explanation:
The new evidence helps in developing a new hypothesis. In this case, new evidence proved that the Chondrichthyes diverged after the evolution of bone had started instead of before the evolution started. This process called atavism where an ancestral genetic trait reappears after having lost. This leads to loss of the traits in the evolution
This can take place by knocking the mutation out to overriding the gene by the old gene or overriding the new trait by the old trait during the evolution period.
Answer:
She is using Karyotyping
Explanation:
A karyotype is the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.
