How Tissues are Made from Cells

Question 1

What is a somatic cell also known as?

Answer 1

Vegetal cell

Question 2

How many chromosomes does a gamete have?

Answer 2

23

Question 3

What is syngamy?

Answer 3

Where the pronuclei of an egg and sperm come together to form a new nucleus

Question 4

What is a 16-cell zygote called?

Answer 4

Morula

Question 5

What is the function of the zona pellucida?

Answer 5

The zona pellucida prevents polyspermy (no more sperm fertilise the egg following the first one)

Question 6

What is a Morula?

Answer 6

A 16-cell zygote

Question 7

The trilaminar disc comprises what 3 germ layers?

Answer 7

Ectoderm
Mesoderm
Endoderm

Question 8

The inner cell mass and outer cell mass gives rise to the _____blast and ______blast

Answer 8

Inner cell mass = Epiblast

Outer cell mass = Hypoblast

Question 9

The epiblast gives rise to what?

Answer 9

The 3 primary germ layers, ectoderm, endoderm, mesoderm

Question 10

The hypoblast gives rise to what?

Answer 10

Extraembryonic endoderm

Question 11

The trophoblast has what function and develops into what?

Answer 11

Provides nutrients to embryo, and develops into the placenta

Question 12

The bilaminar disc comprises what?

Answer 12

Hypoblast and epiblast

Question 13

What does the ectoderm differentiate into?

Answer 13

Nervous system, tooth enamel, epidermis

Question 14

What does the mesoderm differentiate into?

Answer 14

Cardiac muscle, skeletal muscle, smooth muscle, RBCs

Question 15

What does the endoderm differentiate into?

Answer 15

Lung cells, thyroid cells, pancreatic cells

Question 16

What are the types of simple epithelia?

Answer 16

Simple squamous
Simple cuboidal
Simple columnar

Question 17

What are the types of stratified epithelia?

Answer 17

Stratified squamous
Stratified cuboidal
Stratified transitional

Question 18

What are the types of pseudostratified epithelia?

Answer 18

Pseudostratified columnar

Question 19

What are the four main types of cell-cell junctions?

Answer 19

Tight junctions
Adherens junctions
Desmosomes & Hemidesmosomes
Gap junctions

Question 20

Describe what cadherins are

Answer 20

Cadherins are transmembrane proteins, which form homodimers. They require Ca2+. There are three subtypes: E, N, P-Cadherin subtypes, and are found in Adherins junctions and in Desmosomes

Question 21

At gap junctions, what proteins are found?

Answer 21

Connexins

Question 22

Proteoglycans are found in the ECM. Why are they negatively charged?

Answer 22

So they attract positively charged Na+, which helps keep the ECM hydrated

Question 23

Describe the structure of Collagen Type 1

Answer 23

Accounts for 90% of all Collagen. Is a tropohelix of a1, a1, and a2 subunits. Has a high Glycine content (every 3rd residue)

Question 24

Describe what Oesteogenesis Imperfecta is

Answer 24

A genetic condition also known as “Brittle bone disease”, mutation in COL1A1 or COL1A2 genes. Symptoms include brittle bones, blue schlera, hearing loss etc.

Question 25

Describe the biochemical structure of Elastin

Answer 25

Rich in hydrophobic amino acids such as Glycine / Proline - with no hydroxylation

Question 26

Describe the structure of Integrins

Answer 26

Dimer of alpha subunit and beta subunit, with an RGD motif

Question 27

What is the difference between loose connective tissue and dense connective tissue?

Answer 27

Loose connective tissue has less collagen fibres than dense

Question 28

An epithelial cell cancer is known as,.?

Answer 28

Carcinoma

Question 29

A mesenchymal cell cancer is known as..?

Answer 29

Sarcoma

Question 30

A haematopoetic cell cancer is known as…?

Answer 30

Leukemia / Lymphoma

Question 31

A neural cell cancer is known as..?

Answer 31

Glioma / Neuroblastoma

Question 32

As we age, what changes occur to collagen and elastin?

Answer 32

Collagen cross linking increases

Elastin is lost