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
Answer:
i can only define the terms for you.
Explanation:
chromosome - a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
chromatid - each of the two threadlike strands into which a chromosome divides longitudinally during cell division, each containing a double helix of DNA.
gene - a distinct sequence of nucleotides that forms a part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell or virus that may synthesize
It increases..................
Answer:
sympathetic stimulation
Explanation:
Under stress or emergency conditions, the preganglionic neurons of the sympathetic division release acetylcholine. Acetylcholine stimulates secretion and release of epinephrine and norepinephrine from the adrenal medulla. These hormones enhance the effects of the sympathetic division of the autonomic nervous system (ANS) during stress. Epinephrine and norepinephrine augment the fight-or-flight response as they increase the heart rate and force of contraction, the output of the heart, and blood pressure. They also increase blood supply to the heart, liver, and adipose tissue. The airways to lungs become dilated and there are increase blood levels of glucose and fatty acids.
