1.1 Intro to cells

Question 1

Cell theory

Answer 1

1. All living organisms are composed of cells 2. All cells come from pre-existing cells 3. The cell is the smallest unit of life

Question 2

Common features in cells

Answer 2

1. Membrane 2. Genetic material 3. Energy release system 4. Metabolism - chemical reactions powered by enzymes

Question 3

List the functions of life in Paramecium

Answer 3

Metabolism: aerobic respiration, Reproduction: mitosis of nucleus - asexual Sensitivity: cilia help respond to environment Homeostasis: gases enter/leave by diffusion through permeable membrane Excretion: solids - anal pore, liquids - pumped out by vacuoles Nutrition: heterotrophic (endocytosis), food vacuoles digest Growth:

Question 4

List the functions of life in Chlamydomonas

Answer 4

Metabolism: aerobic respiration Reproduction: mitosis - asexual, fusion of nuclei - sexual Sensitivity: flagella help move towards light Homeostasis: diffusion of gases, vacuoles maintain water levels Excretion: waste expelled by diffusion through permeable cell wall Nutrition: autotrophic - photosynthesis Growth:

Question 5

Totipotent Pluripotent Multipotent Unipotent

Answer 5

Teises Politikos Mokslu Universitetas Totipotent: can differentiate into any type of cell, also another organism Ex: blastocyst Pluripotent: can differentiate into any type of cell but NOT another organism Ex: embryonic stem cells Multipotent: can differentiate into closely related cells Ex: bone marrow stem cells into any kind of blood cells Unipotent: can’t differentiate, only divide Ex: skin cells

Question 6

Microscope anatomy

Answer 6

1

Question 7

Compare ELECTRON and LIGHT microscopes

Answer 7

ELECTRON Adv: higher resolution, magnification Disadv: dead specimen, monochrome micrograms (use beam of accelerated e as source of illumination) LIGHT Adv: live specimen, colourful micrographs Disadv: lower resolution, magnification (limited by the wavelength of light)

Question 8

Units m, mm, um, nm, pm

Answer 8

m = 10^0 m mm = 10^-3 m um = 10^-6 m nm = 10^-9 m pm = 10^-12 m

Question 9

Emergent property

Answer 9

Emergent properties arise from the interactions of individual cells to produce new functions in multicellular organisms, ex: life.

Question 10

TEM vs SEM microscopes

Answer 10

Transmission EM: produces 2D images by e that pass through sample (internal images) Scanning EM: produces 3D images by detecting reflected e (surface images)

Question 11

Types of chromatin and function of them

Answer 11

Euchromatin: loosely packed - active genes can be easily transcribed Heterochromatin: tightly packed - inactive genes are not trascribed

Question 12

SCNT method and use

Answer 12

SOMATIC CELL NUCLEAR TRANSFER: method for creating an embryo for stem cells for laboratory/medical use embryo = somatic cell nucleus + enucleated egg cell

Question 13

Nuclear reprogramming

Answer 13

Nuclear reprogramming: identity of a specialised cell can be changed (typically to an embryonic like cell) by making a change in gene expression profile