Biodiversity Section 3 Flashcards
What is DNA?
DNA is an acronym for deoxyribonucleic acid, it’s the blueprint for all living organisms. It’s compared to a ladder called a double helix. The uprights are the backbones of DNA which are made up from sugar and phosphates. The rungs are made up of base pairs.
What are base pairs?
Base pairs are chemicals that are always rung together and paired up inside the double helix structure. G/C ( guanine and cytosine) and A/T (adenine and thiamine.) And the way that these chemicals are rung together creates something called the genetic code.
What are chromosomes?
Chromosomes are found in every cell of your body, and they are the containers for your DNA, that store all your genes. Humans have 46 chromosomes, 23 from your mom and 23 from your dad.
What are genes?
Genes also come in pairs, and they are found on the chromosomes. Each set known as alleles, both alleles carry a set of instructions for the same thing and some may differ from others.
Why do cells divide?
They cannot grow any larger, to repair or replace damaged cells, and for reproduction or growth.
What are the two types of cell division?
The two types of cell division are meiosis and mitosis.
What is meiosis?
Meiosis is when it uses a sperm or an egg. It has two cell divisions and each cell has half the number of chromosomes as the parent. It’s in sexual reproduction and it’s when gametes produce a zygote.
What is Mitosis?
Mitosis is when it makes two cells that are identical and there is only one cell division. Each cell has the same number of chromosomes as the parent, it’s a unicellular organism and body cells. Its asexual reproduction.
What is a dominant gene?
A dominant gene is one strand of DNA that is stronger than the corresponding gene in another strand of DNA. For example; brown eyes and dark hair.
What is a recessive gene?
A recessive gene is when you have one corresponding gene in one strand of DNA that is weaker than the corresponding gene in another strand of DNA.
What’s the difference between purebred and hybrid?
Purebred is when both parents are the same so you u get an offspring that is the same. Hybrid is when parents are different so you get a mixed offspring.
What is homozygous?
Its when two of the same alleles are used for that particular genes. (BB) or (bb).
What is heterozygous?
It’s when one each of the two different alleles are used for that particular gene. (Bb)
What is incomplete dominance?
When two alleles are present and blended together.
Like; red and white alleles = pink petals.
What is Co-Dominance ?
When two alleles are present and visible. For example red and white alleles= red and white striped petals.
