Answer:
In secondary succession, a previously occupied area is re-colonized following a disturbance that kills much or all of its community. A classic example of secondary succession occurs in oak and hickory forests cleared by wildfire. Wildfires will burn most vegetation and kill animals unable to flee the area.
Answer:
Because even though Jupiter is extraordinarily large the sun is still bigger
Explanation:
Jupiter gravitational pull is not large enough to effect objects the size of pleats but it does significantly effect astroids around it. If it became as big as the sun other planets would orbit around it
Answer: A primary caregiver
Explanation:
It is very important that an infant have a primary caregiver as they develop in their early childhood. This is because it will be easier for the infant to bond with the person and begin to trust them for their safety.
This will ensure that their brains develop much more effectively especially in the areas responsible for emotional and social interaction and attachment.
Answer:
Homozygous recessive
Explanation:
The parents of the individual displaying the sickle cell anemia (SS) are phenotypically normal parents meaning, both parents are carriers of the (AS) gene which is a recessive trait for sickle cell anemia.
The individual took up the SS allele from both parents which makes him/her homozygous recessive. An individual is said to be homozygous recessive if that individual carries two copies of the same recessive allele.
Homozygous dominant is when an individual carries two copies of the same dominant allele (e.g AA).
Answer:
AaBb × aabb
Explanation:
A test cross is a cross between an unknown genotype (dominant phenotype) with a homozygous recessive genotype in order to discover the actual genotype of the species exhibiting dominant phenotype.
This is because one allele of a gene is capable of masking the expression of another, the allele masking is called DOMINANT allele while the allele being masked is called RECESSIVE allele. The combination of these two alleles is termed heterozygosity.
An organism that is phenotypically dominant for a specific trait may either be heterozygous or homozygous for that gene. For example, a plant gene for tallness with an dominant allele T, and recessive allele t. This plant will need tall if the genotype is TT (homozygous dominant) or Tt (heterozygous dominant). In order to know which of these genotypes the plant actually has, a test cross is conducted.
In this example, two genes A and B are involved. For the first gene, A represents dominant allele while a represents recessive allele. For the second gene, B represents dominant allele while b represents recessive allele.
In a cross involving parents AABB (homozygous dominant for both genes) and aabb (homozygous recessive for both genes), the F1 progeny will all exhibit phenotypic dominance (AaBb).
However, we cannot know the genotype by merely looking at the phenotype. We cannot ascertain yet whether the dominance is heterozygous or homozygous, hence the need for a test cross.
The test cross is between the dominant F1 progeny and a homozygous recessive i.e. AaBb × aabb. Some of the F2 generation will show recessive traits if the unknown genotype is heterozygous.
