Chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.

The Jack Jumper Ant or Myrmecia pilosula, has only two chromosomes. 2 for females, males are haploid and thus have 1; smallest number possible. Other ant species have more chromosomes.

The African Collared Dove, has 78 chromosomes.

Goldfish, have 94 chromosomes.

A dog, or Canis lupus familiaris, has 78 chromosomes, 76 autosomal and 2 sexual.

Tobacco, or Nicotiana tabacum, has 48 chromosomes. also the cultivated species is a tetraploid.

Genetic Traits (Dominant and Recessive)

Definition of Dominant Genetic Traits:

Dominant traits are traits that are dominant in a group of people; ex. if most people have brown eyes, brown eyes is the dominant trait.

Definition of Recessive Genetic Traits:

Recessive traits are traits that are recessive in a group of people; ex. if most people have brown eyes, as opposed to the small group that have blue eyes, blue eyes are the recessive genes.

Determine Which Observable Genetic Traits are Recessive and Dominant:

Eye Color:

Dominant: Brown

Recessive: Green, and Blue

Hair Color:

Dominant: Brown

Recessive: Blond, and Brown

Widow's Peak:

Dominant: No

Recessive: Yes

Ring-to-Point Finger Size:

Dominant: Equal

Recessive: Pointer, and Ring

Handedness:

Dominant: Right

Recessive: Left, and Both

Hand Grasp:

Dominant: Left

Recessive: Right

Attached/Detached Earlobes:

Dominant: Detached

Recessive: Attached

Tongue Roll:

Dominant: Yes

Recessive: No

Cleft Chin:

Dominant: No

Recessive: Yes

Dimples:

Dominant: No

Recessive: Yes

Freckles:

Dominant: No

Recessive: Yes

Curly Hair:

Dominant: No

Recessive: Yes

Introduction to Genetics

What are we talking about when we say genetics?

When we talk about genetics I think about the strands of deoxyribonucleic acid (DNA), and the combination of two different DNA strands. When these strands merge, some parts of one genetic structure stay, and others are replaced with parts of the other strand. This is what happens when a baby is forming. The baby gets parts of the fathers, and the mothers genetic structure. For example, if most of your relatives from your maternal side have brown hair, you might have brown hair because the hair color is part of your mothers genetic structure, The genetic structure of a certain person can influence all of his or her physical features, as well as some ways of thinking, acting, speaking, hearing, and other mental features. Another thing that can be passed down by genetics are diseases. For example, if your great grand parent had cancer, he can pass down the disease to his children. However, his children might not get cancer, instead they ca pass it down many generations before the disease actually activated.

Even though I have listed many facts about genetics I still have many questions;

1. Can physical and mental disabilities be passed down through genetics?
2. Can memories be passed down through genetics?
3. Do plants have genetic structures?
4. If plants have genetic structures, how are they passed down?

Here are some observable inherited traits;

1. Hair Color
2. Skin Color
3. Eye Color
4. Size