Chromosomes and Meiosis
This section of DNA contains instructions for a functional product.
What is a gene?
An organism with two different alleles for a gene has this genotype.
What is heterozygous?
This term describes an observable characteristic, such as eye colour.
What is a phenotype?
I may be the only cell type that can make gametes, but I stay clean - I promise!
What are germline cells?
What is a population?
The general name for...you know, chromosome 6 and 7, but also 22.
What are autosomes?
In a Tt × Tt cross, this is the percentage of offspring expected to be tt.
What is 25%
A cross between a red-flowered plant and a white-flowered plant, resulting in a pink-flowered plant is an example of this pattern of dominance.
What is incomplete dominance?
The process by which a sperm and egg cell fuse to form a zygote.
What is fertilisation?
Thick fur or webbed feet are examples of this type of adaptation.
What is a structural adaptation?
I want to break free! Just like sister chromatids from each other at this phase of meiosis.
What is anaphase II?
To reveal an unknown dominant genotype, cross the organism with a homozygous recessive one. Name this cross.
What is a test cross?
What are epigenetic factors?
In flowers, pollen from one plant fuses with the ovule of another plant to form an embryo, making it this type of reproduction.
What is sexual reproduction?
Producing concentrated urine to conserve water is an example of this type of adaptation.
What is a physiological adaptation?
A karyotype shows three copies of chromosome 21 instead of two. Name the abnormality.
What is trisomy 21 / Down Syndrome?
I want to work out the probability that my children will have brown hair and blue eyes, so I'll do this kind of cross.
What is a dihybrid cross?
For example, nutrition affects height despite inherited genes.
What is an environmental factor?
Species that reproduce asexually can struggle to survive in changing environments, due to lacking in this important factor.
What is genetic diversity?
Hermit crabs use discarded, empty shells from dead snails for physical protection and shelter, in this kind of interdependency. The snails aren't affected at all.
What is commensalism?
Name the two meiotic processes that create new allele combinations: DNA exchange between chromatids and random distribution of homologous chromosomes.
What are independent assortment and crossing over?
A male has this genotype, showing an X-linked recessive condition.
What is Xa Y?
Don't ever change - but if you do, make sure it's only by this epigenetic modification, which changes gene expression based on how tightly packed the DNA is but not the code itself.
What is histone modification?
This technique for cloning can be used to make an exact copy of an adult individual, from a body cell.
What is somatic cell nuclear transfer (SCNT)?
This kind of distribution indicates individuals gathered around pools of resources.
What is clumped distribution?