What are telotrophic ovariole?
What are telotrophic ovariole?
Telotrophic ovarioles evolved from the polytrophic type when these nurse cells were retained within the germarium. A fourth type of ovariole, the neopanoistic type, has secondarily lost its nurse cells by the development of all cystocytes into oocytes or follicle cells.
In which following ovariole nurse or trophic cells are present?
In polytrophic ovarioles, the trophic cells (also called nurse cells because they ‘nurse’ the oocyte) are grouped near the oocyte to provide necessary macromolecules. They are physically joined to each other and to the oocyte by cytoplasmic bridges.
Is there any relationship between number of ovarioles and fecundity?
Greater numbers of ovarioles in the selected lines were correlated with reduced early age fecundity, but there was no correlation with overall fecundity.
What is Meroistic Oogenesis?
Some insects, such as Drosophila melanogaster, produce eggs by meroistic oogenesis. In this process, the developing oocyte remains connected by cytoplasmic bridges to its sister “nurse” cells, which synthesize molecules and organelles for the future embryo.
What are oviducts?
The oviduct is a structure that transmits the ovum from the ovary to the uterus. 78. It is about 14 cm long and muscular with one end opening into the peritoneal cavity near the ovary and the other into the uterine cavity. It has four segments that gradually phase into one another.
How many ovarioles are present in Queen of termite?
We found that queens in this species had 104.21 ± 12.76 (mean ± SD) ovarioles in total, constituting their left and right ovaries (Table 1).
What is insect ovipositor?
The ovipositor, or egg-laying organ in the female, is often very long and may be modified for piercing, sawing, or stinging. Metamorphosis is complete; i.e., the insect develops through four distinct stages: egg, larva, pupa, and adult.
What are ovarioles in cockroach?
The female reproductive system of cockroach consists of two large ovaries. The ovaries lie laterally in the 12th and 13th segments. Each ovary is formed of a group of eight ovarian tubules or ovarioles. They contain a chain of developing ova.
What is maximum fecundity?
Fecundity is the physiological maximum potential reproductive output of an individual (usually female) over its lifetime and represents one of the major cornerstones of theoretical and applied population biology. Fertility, a related concept, is defined as the current (actual) reproductive performance of an individual.
What is fecundity in population?
Fecundity describes the number of offspring an individual or a population is able to produce during a given period of time (Martin 1995) (Figure 4).
What are the 3 phases of oogenesis?
The process of oogenesis is completed in the following three stages:
- Pre-natal Stage. The primary oocyte grows while being arrested in meiosis-I.
- Antral Stage. The fluid-filled area, present between granulosa cells, combines to form a central fluid-filled space called the antrum.
- Pre-Ovulatory Stage.
What is a primary oocyte?
Primary oocyte is a diploid cell, which is formed from the oogonia or gamete mother cell. Primary oocyte gives rise to secondary oocyte after the first meiotic division.
How many tubes does a woman have?
Most women are born with two healthy fallopian tubes. Also known as uterine tubes or oviducts, these female structures are responsible for the monthly transport of ovum from the ovary to the uterus.
What are the 3 parts of oviduct?
The oviduct is composed of the following three main regions ordered from the ovary toward the uterus: the infundibulum (fimbria in humans), in which most cells are ciliated epithelial cells; the ampulla, which contains large numbers of ciliated epithelial cells and is the site of fertilization; and the isthmus, which …
What are the 5 castes of termites?
We have described that in details. Read that here– why are termites called social insects….We shall now discus these in details: Functions of the different castes system in termite’s nests.
- THE KINGS. The kings are the fertilizers.
- THE QUEENS.
- THE SOLDIERS.
- WINGED REPRODUCTIVES.
Is an ovipositor a stinger?
The stinger is a modified egg-laying apparatus, called an ovipositor, which is attached to poison glands. In aculeate Hymenoptera, eggs emerge from the base of the ovipositor rather than passing through it.
Is the bee stinger an ovipositor?
The bee stinger is a modified ovipositor, although in other insects (and in queen bees) comparable structures are used for laying eggs, in worker bees the stinger is used just for defense. Males therefore do not have stingers and pose no threat.
How many ovarioles are there in cockroach?
So, the correct answer is ‘8’
What is Phallomere in cockroach?
External genitalia in the cockroach. Some chitinous asymmetrical structures are found surrounding the male gonopore at the end of the abdomen. These are three phallomeres or male gonapophyses which constitute the external genitalia.
How many ovarioles are there in a single oviduct?
The constituent ovarioles lead to two oviducts, which converge into a single oviduct. The ovarioles are composed of a germarium and a set of ovarial follicles. In Drosophila melanogaster, there are 16 ovarioles per ovary and there are two ovaries.
What is the most primitive type of ovarioles?
Panoistic ovarioles are believed to be the most primitive of the two types, found in the more primitive insect orders, including the Archeognatha, Thysanura, Odonata, Orthoptera, Plecoptera, and Isoptera. FIGURE 4.8. The three major types of insect ovarioles. A.
How many ovaries does an insect have?
An ovariole is one of the tubes of which the ovaries of most insects are composed. Typically an insect will have two ovaries. The constituent ovarioles lead to two oviducts, which converge into a single oviduct.
What is An ovariole in insects?
An ovariole is one of the tubes of which the ovaries of most insects are composed. Typically an insect will have two ovaries. The constituent ovarioles lead to two oviducts, which converge into a single oviduct. The ovarioles are composed of a germarium and a set of ovarial follicles.