Answer:
The correct answer is - choice 1 in the image.
Explanation:
In this given question there are four phylogenetic trees are given among these four trees one tree shows the milk production to feed young ones which is mologous case in humans, bats, and dogs as they show lactation whereas lizards and birds do not show lactation.
In these four the first option shows the homologous condition at the second branch where milk production is divided from lizard and birds.
Answer:
A common birth defect that is usually due to an extra chromosome 21( trisomy 21) .
Well, I don't fully understand your question. I think I know what you're getting at though.
In a system of sexual reproduction, you have genes coming from both an egg and the sperm. Therefore, it'll only contain half the total amount of chromosomes (46 in humans). A sperm will have 23, and the egg will have the other 23. Is that what you meant why the chromosomes are cut out in pairs? If that wasn't your question, please elaborate and I'll return to answer it to the best of my capabilities.
Eroding the rock slowly away
Good Luck :) !
