Science Term 2 Exam- Biology Flashcards
What are the 2 ways to reproduce?
Asexual reproduction
Sexual reproduction
Why do we reproduce?
Reproduction is to produce offspring, pass on your genetics and to ensure your species doesn’t die out
Asexual reproduction
Only requires 1 organism
Often found in some plants and simple animals
Produces clones of the original parent
- they have the same genetic information
Bad characteristics are reproduced
-If the plant cant survive the frost all of the offspring will be vulnerable in the same way because there is no genetic variation
Pro
-Only one organism, doesn’t need to find a mate
What does DNA stand for
Delxyribose Nucleis Acid
What is a amoeba
The cell that divides into 2 identical cells by mitosis
what is a gene?
a gene is a section of DNA that codes for a specific trait/characteristic
what is a chromosome
a threadlike structure of neucleic acids and protein found in the nucleus of the most living cells, carrying genetic information in the form of genes
Everyone has 23 pairs of chromosomes
In one chromosome there is thousands of genes
Sexual Reproduction
You need 2 organisms You get a set of chromosomes from each Produces a genetic variation Pros -Offspring are different, wont be wiped Cons -Needs 2 organisms that are the opposite gender
Sex cells
Sex cells are called gametes
Male- Sperm, pollen
Female- Egg, ovum (ova)
Each contain 23 chromosomes
When a sperm fertilises a egg it is called a zygote
The cell divides after about 3 days it has become 32 cells and it called a embryo
About 9 weeks all its body systems have developed and it called a feutus
What is a Human Karyotype
A visual representation of chromosomes in the cells nucleus
What is Mitosis?
Mitosis creates a new identical cell
What are codes for DNA?
Thymine (T) goes with Adenine (A)
Cytosine (C) goes with Guanine (G)
S goes on the side of these codes
P goss on the outer of S
Chromosomes
23 Pairs a person, we have 46 in total
Each sex cell has 23
Diploid- When there is pairs of chromosomes
What happens if there are too many chromosomes or too few
The person will have mutations eg physical disabilities, strange physical features and more
What is a somatic cell
A normal body cell
If it went under mitosis an exact replica of the cell would be created