Concordance = presence of the same trait.
Identical twins have a higher rate than fraternal because most of their DNA is identical, it’s identical because the zygote split into two so the babies shared an amniotic sack. (Zygote is fertilized egg) so the baby got duplicated meaning only one egg and sperm created two babies. Fraternal twins happen when two eggs are fertilized and grow in separate amniotic sacks. So two different babies, two different eggs and sperm.
Answer: True
Explanation: They need to replicate their DNA so the daughter cells hold the same genetic information when the parent cell divides
Crayfish are invertebrates which means they don't have a backbone. They are also arthropods, which means that they have a protective exoskeleton on the outside of their body. Other arthropods include insects, spiders, and centipedes. Crayfish continually shed their exoskeleton and regrow a new one. During this transition is when they are most vulnerable to predators because they aren't protected by their outer shell.
Crayfish are found all over the world in many different freshwater environments, such as rivers, creeks, springs, and swamps. But this doesn't necessarily mean that you will be able to find them. They are somewhat cryptic because they dig out homes for themselves under rocks and blend in well with their environment. Crayfish will ardently defend this dwelling against intruders using their strong front claws
They all develop gills, slits and tails
Answer:
Genetic drift is a mechanism of evolution in which allele frequencies of a population change over generations due to chance (sampling error).
Genetic drift occurs in all populations of non-infinite size, but its effects are strongest in small populations.
Genetic drift may result in the loss of some alleles (including beneficial ones) and the fixation.
Genetic drift can have major effects when a population is sharply reduced in size by a natural disaster (bottleneck effect) or when a small group splits off from the main population to found a colony (founder effect).
